We had MM for our recent trip... Here are a few tips:
1. Make sure all the people on your trip are linked on MDE (you have to do this anyways to make FP+ reservations for all members, so not a big problem)
2. Make sure all the adults change their settings on each of their Family and Friends indicating that their pictures can be shared - Click the box under each friend or family that says:
Share PhotoPass Photos
This friend can view and purchase my PhotoPass photos.
3. As long as you are linked, all members of the party's ride photos will be automatically captured and stored (only the person who holds the MM entitlement will be able to see the ride pictures when you go to view them, but they will be there, trust me!)
4. Pictures "expire" 45 days from when they were taken. Once you start downloading photos you have 30 days to continue downloading. You can download them as many times as you want in that time period.
5. Even if you download just one picture it comes as a ZIP file and includes the a copy of the release.
We just downloaded 641 photos from our last trip. Hopes this helps you...